Overbased metal carboxylate precursor and process for making

ABSTRACT

Shelf stable, flowable liquids of overbased alkaline earth metal salts are prepared by reacting an alkaline earth metal base and a carboxylic acid in the presence of a hydrocarbon liquid, a polyol and an alcohol. The resulting overbased alkaline earth metal salts has an alkaline earth metal content of at least about 14.5% and a non-volatile matter content of at least about 95%.

The invention relates to a shelf stable, flowable liquid of an alkalineearth metal salt of a fatty acid and a process for preparing the liquid.More particularly, the invention relates to a shelf stable, flowableprecursor of an overbased alkaline earth metal carboxylate and a processfor preparing the precursor. Even more particularly, the inventionrelates to a shelf stable, flowable precursor of an overbased calciumcarboxylate and a process for preparing the precursor.

BACKGROUND OF THE INVENTION

The preparation of overbased calcium or barium salts of carboxylicacids, alkyl phenols, and sulfonic acids are disclosed in the followingU.S. Pat. Nos. 2,616,904; 2,760,970; 2,767,164; 2,798,852; 2,802,816;3,027,325; 3,031,284; 3,342,733; 3,533,975; 3,773,664; and 3,779,922.The use of these overbased metal salts in the halogen-containing organicpolymer is described in the following U.S. Pat. Nos. 4,159,973;4,252,698; and 3,194,823. The use of overbased barium salt in stabilizerformulations has increased during recent years. This is due, in themain, to the fact that overbased barium salts possess performanceadvantages over the neutral barium salts. The performance advantagesassociated with overbased barium salts are low plate-out, excellentcolor hold, good long-term heat stability performance, goodcompatibility with the stabilizer components, etc. Unfortunately, mostof the overbased barium salts are dark in color and, while these darkcolored overbased barium salts are effective stabilizers forhalogen-containing organic polymer, their dark color results in thediscoloration of the end product. This feature essentially prohibits theuse of dark colored overbased barium salts in applications where a lightcolored polymer product is desired.

According to the teachings of U.S. Pat. No. 4,665,117, light coloredalkali or alkaline earth metal salts are prepared where alkyl phenol isused as a promoter. However, alkyl phenol is also a major cause for thedevelopment of color in the final product. This problem is overcome bythe use of propylene oxide which displaces the hydrogen of the phenolichydroxyl group and thereby restricts the formation of colored species.However, there are disadvantages associated with this approach,principally due to the toxic nature of propylene oxide. Propylene oxideis classified as a possible carcinogen and laboratory animal inhalationstudies have shown evidence of a link to cancer. Propylene oxide is alsolisted as a severe eye irritant, and prolonged exposure to propyleneoxide vapors may result in permanent damage to the eye. Furthermore,propylene oxide is extremely flammable and explosive in nature undercertain conditions. Propylene oxide boils at 94° F. and flashes at −20°F. As a result, extreme precautions are required to handle propyleneoxide at the plant site. Special storage equipment is required forpropylene oxide and other safety features are necessary. U.S. Pat. No.4,665,117 describes the use of propylene oxide at 150° C. At thistemperature, propylene oxide will be in the gaseous phase. Under theseoperating conditions, more than stoichiometric amounts of propyleneoxide are required to carry the reaction to completion because propyleneoxide will escape from the reaction mixture and this requires additionalhandling of the excess propylene oxide.

Liquids of overbased metal carboxylate salts are also used in thepreparation of greases. In particular, grease manufacturing includes amulti-step process and numerous additives to provide propertyenhancements which present an increasing challenge to the specialty,food-grade and bio-based grease formulators. The resulting greaseperformance is also strongly dependent upon the processing conditionssuch as temperature, pressure, residence times and saponificationstoichiometry.

Thixotropic greases or grease-like overbased metal carboxylate or otheroverbased metal-containing compositions having corrosion-inhibitingproperties, and having utility for a variety of uses such as, forinstance, in automobile and truck body undercoatings, and for variousother purposes, are known to the art. Such greases or grease-likecompositions have gone into quite widespread use either as such, oradmixed with other ingredients to produce compositions for use in avariety of environments, and, generally speaking, they are characterizedby reasonably good extreme pressure and antiwear properties, highdropping points, reasonably good resistance to mechanical breakdown,salt spray and water-corrosion resistance, thermal stability at hightemperatures, and other desirable properties.

Whether the liquid of an overbased metal carboxylate salt is utilized inhalogen-containing organic polymers or in the preparation of greases,volatile components, including volatile organic compounds (VOCs), of theoverbased metal carboxylate should be minimized for health, safety andenvironmental reasons.

Notwithstanding the state of the art as described herein, there is aneed for further improvements in preparing overbased alkaline earthmetal salts of fatty acids for use in halogen-containing organicpolymers and in the preparation of greases, wherein the overbasedalkaline earth metal salts have substantially reduced levels of volatilecomponents within the final product.

SUMMARY OF THE INVENTION

In general, one aspect of the invention is to provide a shelf stableliquid of an overbased alkaline earth metal salt of a fatty acid,wherein the alkaline earth metal content is at least about 14.5% and thenon-volatile matter content is at least about 95%.

In yet another aspect of the invention, a shelf stable, flowable liquidof an overbased alkaline earth metal salt of a fatty acid is provided.The liquid includes at least one hydrocarbon liquid, a polyol, analcohol, wherein the alcohol has at least 8 carbon atoms, and anoverbased alkaline earth metal salt of a fatty acid, wherein thealkaline earth metal salt has an alkaline earth metal content of atleast about 14.5% and a non-volatile matter content of at least about95%.

In another aspect of the invention, a method for preparing a shelfstable, flowable liquid of an overbased alkaline earth metal salt of afatty acid is provided, the method includes the steps of:

(a) preparing a precursor mixture comprising a carboxylic acid, whereinthe carboxylic acid is a fatty acid; at least one hydrocarbon liquid; apolyol; and an alcohol, wherein the alcohol has at least 8 carbon atoms;

(b) neutralizing the carboxylic acid with an initial amount of alkalineearth metal base to form an alkaline earth metal carboxylate precursormixture;

(c) heating the alkaline earth metal carboxylate precursor mixture;

(d) adding an additional amount of an alkaline earth metal base to thealkaline earth metal carboxylate precursor mixture;

(e) carbonating the precursor mixture to neutrality;

(f) filtering the precursor mixture; and

(g) distilling the precursor mixture until an alkaline earth metalcontent of at least about 14.5% and a non-volatile matter content of atleast about 95% is achieved.

These and other advantages and novel features of the present invention,as well as details of an illustrated embodiment thereof, will be morefully understood from the following description.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a graph of a thermogravimetric analysis of a shelf stable,flowable liquid of an overbased alkaline earth metal salt of a fattyacid in one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment of invention, a shelf stable, flowable liquid of anoverbased alkaline earth metal salt of a fatty acid prepared from aprecursor includes an alkaline earth metal carbonate, an alkaline earthmetal carboxylate of a fatty acid, a liquid hydrocarbon, and an alcoholhaving at least 8 carbon atoms, with the liquid having alkaline earthmetal content is at least about 14.5% and the non-volatile mattercontent is at least about 95%.

The alkaline earth metal of the salt of the overbased alkaline earthmetal salt of the fatty acid precursor may be selected from the groupconsisting of calcium, barium, magnesium and strontium. These metals maybe derived from metal oxides and hydroxides, and in some instances,metal sulfides and hydrosulfides. For example, the alkaline earth metalsalt may include a calcium carboxylate.

The carboxylic acid portion of the overbased alkaline earth metal saltprecursor, may include fatty acids, including C₈-C₃₀ saturated,unsaturated carboxylic acids of 8 to 30 carbon atoms, either alone or incombination with each other, or reactive equivalents of carboxylicacids. Examples of useful carboxylic acids and fatty acids include butare not limited to caprylic acid, capric acid, lauric acid, myristicacid, myristoleic acid, 2-ethylhexanoic acid, decanoic acid, dodecanoicacid, pentadecanoic acid, palmitic acid, palmitoleic acid, stearic acid,12-hydroxystearic acid, oleic acid, ricinoleic acid, linoleic acid,linoleic acid, arachidic acid, gadoleic acid, behenic acid, erucic acid,and mixtures of any of these acids.

The shelf stable, flowable liquid of an overbased alkaline earth metalsalt of the fatty acid precursor of the present invention may alsoinclude an alcohol that promotes the formation of the overbased alkalineearth metal carboxylate. The alcohol includes aliphatic alcohols thatcontain at least 8 carbon atoms. In one example, an aliphatic alcoholhaving a range from about 8 to about 18 carbon atoms may be used.Examples of such aliphatic alcohols include isodecanol, dodecanol,octanol, tridecanol, tetradecanol or mixtures thereof. It has been foundthat when a higher aliphatic alcohol is employed in making the overbasedproduct, phenol may be excluded from the reaction as a promoter.

The shelf stable liquid of an overbased alkaline earth metal salt of thefatty acid precursor of the present invention may also include a polyol.The polyol can be a glycol or glycol ether. The glycol or glycol ethermay be selected from the group consisting of diethylene glycol monobutylether (butyl Carbitol®, triethylene glycol, hexylene glycol, propyleneglycol, dipropylene glycol, diethylene glycol monomethyl ether, ethyleneglycol monobutyl ether, and mixtures thereof.

In another embodiment of the present invention, a liquid base oil mayalso be employed for preparing the overbased precursor materials. Thebase oil can be a hydrocarbon liquid that generally includes anyhydrocarbon diluent. Most generally, the liquid hydrocarbon is selectedfrom the group of hydrocarbon oils, mineral spirits, non-aromatichydrocarbons and polyalphaolefins (PAOs). In one embodiment of theinvention, suitable hydrocarbon liquids include SHELLSOL™ D70 and D80commercially available from Shell Chemical. In yet another embodiment,the PAOs are utilized, either alone or in combination with other liquidhydrocarbons, as suitable liquid hydrocarbons for preparing theoverbased precursor material since they have flexible alkyl branchinggroups on every other carbon of their polymer backbone chain. Thesealkyl groups, which can shape themselves in numerous conformations, makeit very difficult for the polymer molecules to line themselves upside-by-side in an orderly way. Furthermore, many PAOs are relativelystable at higher temperatures and typically have a tendency not tocrystallize or solidify at lower temperatures since they are able toremain as oily, viscous liquids.

In yet another embodiment of the invention, the process for preparing ashelf stable liquid of an overbased alkaline earth metal salt of a fattyacid precursor includes reacting an alkaline earth metal base and afatty acid with an equivalent ratio of metal base to the fatty acidbeing greater than 1:1 in the presence of a at least one liquidhydrocarbon, an alcohol, and a glycol ether. The mixture may beacidified and carbonated to produce amorphous alkaline earth metalcarbonate within the mixture. During carbonation, a dispersion may beadded containing alkaline earth metal base, liquid hydrocarbon and analcohol having at least 8 carbon atoms in relative amounts at acontrolled rate of base addition to produce a stable haze free liquidreaction product. During the reaction, water is removed from thereaction product to produce a shelf stable, flowable liquid overbasedalkaline earth metal salt. Generally, the entire process may beconducted in the absence of free oxygen and, for this purpose, anatmosphere of nitrogen may be used.

Throughout this specification and claims, the term “basic” or“overbased” as applied to the alkaline earth metal salts is used torefer to metal compositions wherein the ratio of total metal containedtherein to the fatty acid moieties is greater than the stoichiometricratio of the neutral metal salt. That is, the number of metalequivalents is greater than the number of equivalents of the fatty acid.In some instances, the degree to which excess metal is found in thebasic metal salt is described in terms of a “metal ratio”. Metal ratioas used herein indicates the ratio of total alkaline earth metal in theoil-soluble composition to the number of equivalents of the fatty acidor organic moiety. The basic metal salts often have been referred to inthe art as “overbased” or “superbased” to indicate the presence of anexcess of the basic component.

It has been found important during carbonation to add the dispersion ofmetal base, liquid hydrocarbon and aliphatic alcohol in relative amountsat a controlled rate to produce the stable reaction product. There are anumber of reasons which are believed to contribute to the formation of astable liquid which is then filterable to remove impurities andbyproducts of the reaction. It has been determined that by thecontinuous addition of the dispersion or slurry of base duringcarbonation, such results are achievable. It is believed that the metalbase slurry prevents the formation of undesirable calcium carbonatecrystals or byproducts in the desired overbased metal salt. Theseundesirable moieties prevent the formation of stable products which arefilterable. Thus, the metal base slurry is added at a controlled ratewhich does not exceed the rate of the desired product-forming reaction.The reaction is controlled by continuous or incremental addition of themetal base to make the calcium ions immediately available for thedesired reaction as opposed to allowing the metal base, for examplelime, to react and form a byproduct. Excessive byproduct or lime coatedwith calcium carbonate is believed to render the liquid productunalterable. Using this procedure, the pH is controlled during thereaction so that the fatty acid is neutralized and the pH rises to about7-10 with the continued addition of base to produce dissolved metal ionwhich reacts with CO₂ during carbonation to produce the desired product.It is believed if the reaction rate is not controlled, and the base isnot dissolved, then solid base reacts or is coated with calciumcarbonate to form undesirable byproducts. The formation of undesirablebyproducts of the reaction renders the final product unstable andunfilterable.

As developed above, one of the features of the method is the step ofadding during carbonation a dispersion of an alkaline earth metal base,polyol, liquid hydrocarbon and an alcohol having at least 8 carbon atomsat a controlled rate of base addition to produce the stable, flowableliquid. It has been determined that the addition of a dispersion of thebase in the liquid hydrocarbon and aliphatic alcohol protects orpassivates the base, thereby enabling the formation of a stable,flowable liquid reaction product. By protecting or passivating the base,carbonation proceeds to produce amorphous alkaline earth metalcarbonate. Unexpectedly, the reaction proceeds without the need toremove water during the reaction and results in a shelf stable liquidreaction product.

The amount of alkaline earth metal base utilized in the preparation ofbasic salts is an amount which is more than one equivalent of the baseper equivalent of fatty acid or organic moiety, and more generally, willbe an amount sufficient to provide at least three equivalents of themetal base per equivalent of the acid. Larger amounts can be utilized toform more basic compounds, and the amount of metal base included may beany amount up to that amount which is no longer effective to increasethe proportion of metal in the product. When preparing the mixture, theamount of fatty acid and the alcohol included in the mixture should begreater than 1:1 in order to provide a basic product. More generally,the ratio of equivalents will be at least 3:1.

The ratios of hydrocarbon oil to alcohol (dodecanol) are about 2:1 toabout 4:1 in one embodiment of the invention. The glycol ether may beused at about 1-15% of the final product.

The lime slurry which is added to the oleic acid in the reaction isformulated to be a pumpable mixture with the general composition ofabout 40-50% lime, about 25-40% hydrocarbon oil, about 10-25% dodecanol,and about 0-10% propylene glycol. The propylene glycol amount that isneeded to make a pumpable slurry increases as the percentage of lime inthe slurry increases.

The process for preparing the shelf stable, flowable overbased calciumcarboxylate precursor includes the reaction of an alkaline earth metalbase and a carboxylic acid to form an alkaline earth metal carboxylatemixture, with an equivalent ratio of metal base to the carboxylic acidgreater than 1:1 in the presence of a liquid hydrocarbon, an aliphaticalcohol, and a glycol ether. In one embodiment, the carboxylic acid is afatty acid, the fatty acid being oleic acid, the liquid hydrocarbon isSHELLSOL™ D80, the alcohol is dodecanol, and the glycol ether ispropylene glycol. The mixture is acidified, through a process ofcarbonation, to produce amorphous alkaline earth metal carbonate, forexample calcium carbonate. The step of carbonation involves treating themixtures described above with an acidic gas in the absence of freeoxygen until the titratable basicity is determined usingphenolphthalein. Generally, the titratable basicity is reduced to a basenumber below about 10. The mixing and carbonation steps require nounusual operating conditions other than the exclusion of free oxygen.

By the term “acidic gas” as used in this specification and in the claimsis meant a gas which upon reaction with water will produce an acid.Thus, such gases as sulfur dioxide, sulfur trioxide, carbon dioxide,carbon disulfide, hydrogen sulfide, etc., are exemplary of the acidicgases which are useful in the preparation of the overbased metalcarboxylates disclosed. When carbon dioxide is used the alkaline earthcarbonate is formed. When the sulfur gases are used, the sulfate,sulfide and sulfite salts are formed.

During carbonation, the alkaline earth metal base, polyol, liquidhydrocarbon and alcohol may be added in relative amounts at a controlledrate of base addition. In one embodiment of the invention, the dryalkaline earth metal base, polyol, liquid hydrocarbon and alcohol may beslurried to facilitate mixing during the carbonation process. Water isremoved from the reaction product to produce a shelf stable, flowableliquid of an alkaline earth metal salt of a fatty acid. Generally, theprocess be conducted in the absence of free oxygen and, for thispurpose, an atmosphere of nitrogen is used.

During carbonation the mixture may be heated to a temperature which issufficient to drive off some of the water contained in the mixture orthe water generated during the reaction of the base and the carboxylicacid can be retained during the overbasing reactions. The treatment ofthe mixture with the carbon dioxide preferably is conducted at elevatedtemperatures, and the range of temperatures used for this step may beany temperature above ambient temperature in the range from about 75° C.(about 165° F.) to about 200° C. (about 390° F.). Higher temperaturesmay be used such as 250° C. (about 480° F.), but there is no apparentadvantage in the use of such higher temperatures. Ordinarily, atemperature of about 80° C. (about 175° F.) to 150° C. (about 300° F.)is satisfactory.

Other features of the method include filtering the product of thereaction to produce a shelf stable liquid precursor at a productfiltration rate of at least about 300 ml per 10 minutes. In oneembodiment of the invention, the product which is produced is filterableto remove unwanted byproducts and enhance the shelf stability of theoverbased liquid. For example, with a Buchner funnel under vacuum ofabout 25-30 inches Hg with a Whatman No. 1 filter and a diatomaceousearth filtering aid, the product is filterable at satisfactory rates.Thus, filtration removes undesirable impurities including silica, ironoxide and other metal species, unreacted calcium hydroxide, calciumcarbonate, and other oxides which may contribute to lack of stability.

In another aspect of the invention, the liquid overbased alkaline earthsalt of the fatty acid precursor is believed to be a thermodynamicallystable microemulsion. The microemulsion has micelles and a continuousphase. The micelles consist of an alkaline earth metal carbonate and analkaline earth metal carboxylate of the fatty acid. The continuous phaseof the microemulsion consists of the liquid hydrocarbon and the alcohol.

In yet another embodiment of the invention, after the removal of waterfrom the precursor of the alkaline earth metal base, fatty acid, polyol,liquid hydrocarbon and alcohol, the precursor is distilled or vacuumstripped at a temperature up to about 165° C. (about 330° F.) to removethe volatile components of the reaction product. In distillationterminology, “stripping” refers to the removal of a volatile componentfrom a less volatile substance. The vacuum stripping proceeds until thefinal product has a measured alkaline earth metal content of at leastabout 14.5% and a non-volatile matter content of at least about 95%.

In still yet another embodiment of the invention, the vacuum strippingof the precursor yielded an unexpected result. In particular, it waspreviously believed that in order to maintain a stable microemulsion ofthe liquid overbased alkaline earth salt of the fatty acid, the liquidhydrocarbon and alcohol components of the continuous phase were bothnecessary in the final reaction product. However, it was unexpectedlyobserved that upon subjecting the precursor to vacuum stripping, notonly did the final product maintain its shelf stable and flowable liquidproperties, but it was determined that the final product had a finalnon-volatile matter content of at least 95% and a flash point of greaterthan 93° C. (about 200° F.).

The reaction mixture for an overbased calcium oleate, after addition ofthe slurry and carbonation with carbon dioxide and after vacuumstripping, has the following composition ranges:

-   Calcium oleate about 15-40% by weight-   Calcium carbonate about 9-35% by weight-   Hydrocarbon oil about 25-35% by weight-   Dodecanol (co-surfactant) less than about 5% by weight-   Propylene glycol less than about 1% by weight

Substitution of magnesium, strontium, or barium for calcium in theoverbased salt is done on an equivalent basis of the metal hydroxide. Onthe basis of the final reaction mixture prior to vacuum stripping, thefollowing amounts may be used:

-   Ca(OH)₂ (lime) about 15-35% by weight-   Mg(OH)₂ about 12-24% by weight-   Sr(OH)₂ about 25-50% by weight-   Ba(OH)₂ about 35-50% by weight

The following Examples illustrate the preparation of the shelf stablehaze free liquids of the overbased salts in accordance with the methodof the present invention, but these examples are not considered to belimiting the scope of this invention. Unless otherwise indicated in thefollowing examples and elsewhere in the specification and claims, allparts and percentages are by weight, and all temperatures are in degreesFahrenheit.

EXAMPLES Formation of Overbased Calcium Oleate Precursor I Example 1

A 15% overbased calcium oleate/carbonate was prepared according to thisExample. A mixture of about 274.3 g of oleic acid, about 270.0 g ofD-80, about 140.3 g of dodecanol, about 50.0 g of propylene glycol andabout 25.0 g of water was heated to about 88° C. (about 190° F.), withstirring, under a nitrogen atmosphere. To the stirred mixture there wascontinuously added a dispersion comprised of about 140.4 g of D-80,about 85.0 g of dodecanol, about 25.0 g of propylene glycol and about276.7 g of lime for about 50 minutes to produce a solution of calciumoleate in the mixture. At this point in the reaction, the mixture testedbasic with phenolphthalein (about 10-12 pH). Then, to the stirredmixture there was continuously added, over a period of about 3 hours,the mixture was treated with carbon dioxide at 1.5 SCFH at about 93° C.(about 200° F.). The basicity of the reaction was checked to maintainthe basicity during the reaction. When the reaction mixture testednearly neutral to phenolphthalein, the carbon dioxide addition wasdiscontinued. The reaction mixture was then heated to about 149° C.(about 300° F.), and a total of 85.2 g of water was removed via aDean-Stark trap. The resulting product mixture was stirred and 24.00 gof filter aid (diatomaceous earth) was added. The product mixture wasfiltered with suction, as stated above in the description, at over 500ml per 10 minutes, yielding a shelf stable, flowable liquid filtrate ofoverbased calcium oleate/carbonate which remained shelf stable uponcooling to room temperature.

Vacuum Stripping of Overbased Calcium Oleate Precursor I Example 2

A 250 ml three neck round bottom flask was charged with the precursorobtained in Example 1. The three neck round bottom flask was then fittedwith a nitrogen inlet to sparge the mixture in one neck of the flask, atemperature probe in another neck of the flask and a vacuum line in theother neck of the flask. The vacuum filtration was conducted at atemperature between about 149° C. (about 300° F.) and about 163° C.(about 325° F.) with the nitrogen gas supplied at a rate of 6 cubic feetper hour (SCFH). A total distillate of about 678.6 g was collectedyielding a non-volatile matter content of about 84.2% and the filtratewas analyzed to contain about 14.8% calcium by weight. After theaddition of about 50.0 g 6.0 cSt PAO to the mixture, further vacuumfiltration was conducted as described above. After an additional threehours of filtration, it was determined that the mixture had anon-volatile matter content of about 99.4% and the filtrate was analyzedto contain about 15.7% calcium by weight. The final product had thefollowing physical properties:

-   Flash point—>200° C. (about 392° F.)-   Specific gravity—about 1.162-   Weight per gallon—9.68-   % Volatile by volume—<1-   % Volatile by weight—<1

As seen in FIG. 1, a graph of a thermogravimetric analysis (TGA) of thevacuum-stripped final product is provided. The analysis was conductedusing a Seiko 5200 TG/DTA. The sample was evaluated from about 30° C.(about 86° F.) to about 550° C. (about 1022° F.) at a rate of 10°C./min. The thermogram (TG %) of the final product shows thedecomposition of the final product as a function of temperature. Theweight loss profiles, as designated by inflection points on the TG %curve of the final product, were determined to be 86.3% at 298.2° C.(about 568° F.), 56.99% at 436.9° C. (about 819° F.) and 38.6% at 496.0°C. (about 925° F.). The inflection points represent a point ortemperature on a curve at which the curvature of the plot changes signduring the decomposition of the various components of the final product,including various forms of calcium carbonate including calcite, vateriteand/or aragonite if present. The inflection points are represented bythe first derivative curve (DTG %/min). These results suggest that thevacuum-stripped final product of the shelf stable, flowable overbasedalkaline earth salt of the fatty acid has a non-volatile matter contentgreater than 95% when measured at 200° C. (about 392° F.).

Formation of Overbased Calcium Oleate Precursor II Example 3

A 15% overbased calcium oleate/carbonate was prepared according to thisExample. A mixture of about 274.3 g of oleic acid, about 270.0 g ofD-80, about 140.3 g of dodecanol, about 50.0 g of propylene glycol,about 100.0 g of 6.0 cSt PAO and about 25.0 g of water was heated toabout 88° C. (about 190° F.), with stirring, under a nitrogenatmosphere. To the stirred mixture there was continuously added adispersion comprised of about 140.4 g of D-80, about 85.0 g ofdodecanol, about 25.0 g of propylene glycol, about 50.0 g of 6.0 cSt PAOand about 277.0 g of lime for about 50 minutes to produce a solution ofcalcium oleate in the mixture. At this point in the reaction, themixture tested basic with phenolphthalein (about 10-12 pH). Then, to thestirred mixture there was continuously added, over a period of about 3hours, the mixture was treated with carbon dioxide at 1.5 SCFH at about93° C. (about 200° F.). The basicity of the reaction was checked tomaintain the basicity during the reaction. When the reaction mixturetested nearly neutral to phenolphthalein, the carbon dioxide additionwas discontinued. The reaction mixture was then heated to about 149° C.(about 300° F.), and a total of about 110.0 g of water was removed via aDean-Stark trap. The resulting product mixture was stirred and 26.00 gof filter aid (diatomaceous earth) was added. The product mixture wasfiltered with suction, as stated above in the description, at about 1000ml in about 5.5 minutes and about 1225 ml in about 7 minutes, yielding ashelf stable, flowable liquid filtrate of overbased calciumoleate/carbonate which remained shelf stable upon cooling to roomtemperature.

Vacuum Stripping of Overbased Calcium Oleate Precursor II Example 4

The procedure according to Example 3 was repeated and the filtrate fromboth procedures, which resulted in a total of about 2,032 g of product,was combined and prepared for vacuum stripping. A three neck roundbottom flask was charged with the precursor material obtained in the twopreparations according to Example 3. The three neck round bottom flaskwas then fitted with a nitrogen inlet to sparge the mixture in one neckof the flask, a temperature probe in another neck of the flask and avacuum line in the other neck of the flask. The vacuum filtration wasconducted at a temperature between about 149° C. (about 300° F.) andabout 163° C. (about 325° F.) with the nitrogen gas supplied at a rateof 6 cubic feet per hour (SCFH). About 7.5 hours into the vacuumstripping of the sample, the non-volatile matter content was determinedto be about 95.3% and the filtrate was analyzed to contain about 15.7%calcium by weight. After the addition of about 25.0 g of 6.0 cStpolyalphaolefin (PAO) to the mixture, further vacuum filtration wasconducted as described above. After an additional four hours offiltration, it was determined that the mixture had a non-volatile mattercontent of about 98.2% and the filtrate was analyzed to contain about15.7% calcium by weight. An additional amount of about 45.0 g of 6.0 cStPAO was added to the mixture in order to adjust the final calciumcontent measured to be about 15.3% calcium by weight. The final producthad the following physical properties:

-   Flash point—>200° C. (about 392° F.)-   Specific gravity—about 1.144-   Weight per gallon—9.53-   % Volatile by volume—<1-   % Volatile by weight—<1

Based upon the foregoing disclosure, it should now be apparent that theoverbased, shelf stable, flowable liquid of an alkaline earth metal saltof a fatty acid and a process for preparing the liquid as describedherein will carry out the objects set forth hereinabove. It is,therefore, to be understood that any variations evident fall within thescope of the claimed invention and thus, the selection of specificcomponent elements can be determined without departing from the spiritof the invention herein disclosed and described.

1. A shelf stable, flowable liquid of an overbased alkaline earth metalsalt of a fatty acid, the liquid comprising: at least one hydrocarbonliquid; a polyol; an alcohol, wherein the alcohol has at least 8 carbonatoms; and an overbased alkaline earth metal salt of a fatty acid,wherein the alkaline earth metal salt has an alkaline earth metalcontent of at least about 14.5% and a non-volatile matter content of atleast about 95%.
 2. The liquid of claim 1, wherein the fatty acid is aC₁₂-C₂₂ fatty acid.
 3. The liquid of claim 2, wherein the fatty acid isoleic acid.
 4. The liquid of claim 1, wherein an alkaline earth metal ofthe overbased alkaline earth metal salt is selected from the groupconsisting of calcium, barium, magnesium and strontium.
 5. The liquid ofclaim 1, wherein the overbased alkaline earth metal salt is calciumoleate.
 6. The liquid of claim 1, wherein the alcohol is an aliphaticalcohol of at least 14 carbon atoms.
 7. The liquid of claim 1, whereinthe polyol is a glycol or a glycol ether selected from the groupconsisting of diethylene glycol monobutyl ether, propylene glycol,hexylene glycol, triethylene glycol, dipropylene glycol, diethyleneglycol monomethyl ether, ethylene glycol monobutyl ether, and mixturesthereof.
 8. A method for preparing a shelf stable, flowable liquid of anoverbased alkaline earth metal salt of a fatty acid, the methodcomprising the steps of: (a) preparing a precursor mixture comprising acarboxylic acid, wherein the carboxylic acid is a fatty acid; at leastone hydrocarbon liquid; a polyol; and an alcohol, wherein the alcoholhas at least 8 carbon atoms; (b) neutralizing the carboxylic acid withan initial amount of alkaline earth metal base to form an alkaline earthmetal carboxylate precursor mixture; (c) heating the alkaline earthmetal carboxylate precursor mixture; (d) adding an additional amount ofan alkaline earth metal base to the alkaline earth metal carboxylateprecursor mixture; (e) carbonating the precursor mixture to neutrality;(f) filtering the precursor mixture; and (g) distilling the precursormixture until an alkaline earth metal content of at least about 14.5%and a non-volatile matter content of at least about 95% is achieved. 9.The method of claim 8, wherein the fatty acid is a C₁₂-C₂₂ fatty acid.10. The method of claim 9, wherein the fatty acid is oleic acid.
 11. Themethod of claim 8, wherein the alkaline earth metal is selected from thegroup consisting of calcium, barium, magnesium and strontium.
 12. Themethod of claim 8, wherein the alkaline earth metal carboxylateprecursor mixture includes calcium oleate and calcium carbonate.
 13. Themethod of claim 8, wherein the alcohol is an aliphatic alcohol of atleast 12 carbon atoms.
 14. The method of claim 8, wherein the polyol isa glycol or a glycol ether selected from the group consisting ofdiethylene glycol monobutyl ether, propylene glycol, hexylene glycol,triethylene glycol, dipropylene glycol, diethylene glycol monomethylether, ethylene glycol monobutyl ether, and mixtures thereof.
 15. Themethod of claim 8, wherein the precursor mixture is distilled withvacuum stripping.